A semiconductor die is fabricated by dicing a 6-inch large or 8-inch large wafer into dice of a predetermined size. When dicing, an adhesive retaining tape is attached on a back surface of a wafer so that semiconductor dice may not fall apart after dicing, and the wafer is diced from a front surface using a dicing saw or the like. At this time, the retaining tape on the back surface is slightly cut into but not cut off, and retains the semiconductor dice. Then, the semiconductor dice that have been diced are picked up one by one from the retaining tape, and transferred to the next step such as die bonding.
Conventionally, as a method of picking up the semiconductor dice from an adhesive retaining tape, a method using a plunge-up needle is commonly used (see FIG. 15 in Patent Document 1, for example). According to this method, the center of the semiconductor die is plunged up with a plunge-up needle from under a retaining sheet to which a tensile force is applied toward a surrounding area in a state in which the semiconductor die is suctioned with a collet, the adhesive retaining sheet is separated from the semiconductor die by the tensile force applied to the retaining sheet, and the semiconductor die is picked up with the collet.
However, this method using the plunge-up needle has a problem that the semiconductor die may become broken by being plunged up if the semiconductor die is thin, and therefore it becomes difficult to use this method in picking up of recent thin semiconductor dice.
Thus, there have been proposed methods of separating and picking up the semiconductor die from an adhesive retaining sheet without using a plunge-up needle. As an example, Patent Document 1 proposes a method of: providing a projecting portion whose width is smaller than that of the semiconductor die to be picked up on a front surface of a stage; providing suction holes in the front surface of the stage around the projecting portion; when picking up the semiconductor die, placing the semiconductor die to be picked up on the projecting portion so that the semiconductor die to be picked up sticks out from the projecting portion and held with a collet; vacuum-suctioning a retaining sheet downward through the suction holes to separate a portion of the retaining sheet that sticks out from the projecting portion off from the semiconductor die; and thereafter moving the projecting portion horizontally with the stage front surface while the semiconductor die is being suctioned with the collet to separate the remaining portion of the retaining sheet from the semiconductor die (see FIG. 9 to FIG. 10 in Patent Document 1).
Further, Patent Document 2 proposes a method of: providing suction openings in a contact surface of a stage; when picking up the semiconductor die, causing a tip end of a cover that opens and closes the suction opening to be advanced from the contact surface; causing the cover to slide while pushing up a retaining sheet and the semiconductor die to sequentially open the suction openings; sequentially causing the opened suction openings to suction the retaining sheet and separate the retaining sheet; and causing a collet that stands by above the semiconductor die to sequentially suction the semiconductor die, thereby picking up the semiconductor die (see FIG. 11 and FIG. 13 in Patent Document 2).